The present invention relates to a communication system, a bus load monitoring device, and a bus load monitoring method, and can be preferably used in, for example, a bus load monitoring device that monitors the load of a CAN (Controller Area Network) bus.
As one of in-vehicle LANs (Local Area Networks) mounted in a car, a CAN has been known. In the CAN, a plurality of ECUs (Electronic Control Units) controlling each of a plurality of systems such as an engine system and a steering wheel/brake system is coupled to a CAN bus. Further, the CAN buses are coupled to each other via a GW (Gateway).
In recent years, response to security has been required for cars, and the needs of monitoring the load of the CAN bus have been increased as part of security.
As a related technique of monitoring the load of the CAN bus, there is a technique disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2006-287738. According to Japanese Unexamined Patent Application Publication No. 2006-287738, a GW monitors the load of a CAN bus.